NEET physics
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If force (F), velocity (v) and time (T) are taken as fundamental units, then the dimensions of mass are
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[FvT-1]
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[FvT-2]
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[Fv-1T-1]
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[Fv-1T]
D.
[Fv-1T]
We know that,
F = ma
That is,
F = mv/t
So, 
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A projectile is fired from the surface of the earth with a velocity of 5 m/s and angle 
with the horizontal. Another projectile fired from another planet with a velocity of 3 m/s at the same angle follows a trajectory which is identical with the trajectory of the projectile fired from the earth. The value of the acceleration due to gravity on the planet is,
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3.5
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5.9
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16.3
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110.8
A.
3.5
If the trajectory is same for both the projectiles, their maximum height will be the same.
That is,
(Hmax)1 = (Hmax)2
i.e., 
A particle is moving such that its position coordinates (x,y) are (2m, 3m) at time t = 0, (6m, 7m) at time t = 2 sec and (13 m, 14m) at time t= 5 sec. Average velocity vector (vav) from t = 0 to t = 5 s is,
D.
Average velocity vector,
A system consists of three masses m1, m2 and m3 connected by a string passing over a pulley P. The mass m1 hangs freely and m2 and m3 are on a rough horizontal table (the coefficient of friction= 
). the pulley is frictionless and of negligible mass. The downward acceleration of mass m1 is,
C.
First of all consider the forces on the blocks,
For the 1st block,
mg - T1 = m x a ... (i)
Let us consider second and third block as a system,
Then,
T1 - 
= 2m x a
mg (
) = 3m x a
The force F acting on a particle of mass m is indicated by the force-time graph as shown below. The climate change in momentum of the particle over the time interval from zero to 8 s is,
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24 Ns
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20 Ns
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12 Ns
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6 Ns
C.
12 Ns
The area under F-t graph gives change in momentum.
For 0 to 2 s,
For 2 to 4 sec,
For 4 to 8 sec,
So, total change in momentum for 0 to 8 sec is,
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